The program prioritizes actions at the highest-volume production and midstream sites and includes efforts to develop and deploy new, more efficient technologies to detect and reduce facility emissions. All aspects of the program are voluntary, except for some mandatory leak detection and repair surveys, which vary by U.S. location and regulatory requirements. XTO Energy’s leak-detection-and-repair efforts and operational improvements at U.S. production and midstream sites have reduced estimated methane emissions across ExxonMobil operations by 2 percent in the past year.
Reporting: Our efforts are discussed in this report, as well as in other materials available on our website, where the company reports 10 years of performance data on overall ExxonMobil methane emissions. In the United States in 2017, XTO Energy reported 169,000 metric tons (4.2 million metric tons equivalent of CO2) of methane emissions. Over 7,200 metric tons of methane (180,000 metric tons equivalent of CO2) were mitigated due to XTO Energy’s voluntary methane emissions program and other operational improvements. XTO Energy-operated production operations emissions equate to about 374 metric tons of methane per million barrels of oil-equivalent production, an emissions rate of 0.32 percent. XTO Energy accounts for nearly two-thirds of ExxonMobil’s methane emissions.
High-bleed pneumatic phase-out: Over the next three years, we are voluntarily switching out more than 1,000 high-bleed pneumatic devices for lower or no-bleed devices that can significantly reduce emissions.
Leak detection and repair: We have implemented an enhanced leak detection and repair program that prioritizes our largest-volume sites and greatest opportunities for emission reductions. Planned events such as liquid unloading will be managed to reduce the release of methane emissions to the atmosphere. Liquid unloading removes liquid that has collected in equipment tubing and prevents natural gas from flowing up through the well. As part of our program, field personnel monitor and remain in close proximity during the manual unloading process to close all wellhead vents to the atmosphere.
Training: ExxonMobil is currently developing an enhanced training program to complement these efforts.
Improved facility designs: We continue evaluating opportunities to upgrade facilities to reduce emissions. This includes research in collaboration with equipment manufacturers to develop state-of-the-art, low-cost, minimum-emissions equipment.
Research: As part of the company’s efforts to better understand the magnitude and characteristics of oil and gas industry-related methane emissions, ExxonMobil participated in studies conducted by the University of Texas and the Environmental Defense Fund. The studies quantified methane leakage rates in the United States from Upstream gas production activities at 0.4 percent of the total gas produced. ExxonMobil remains active in ongoing methane research, including participation in a methane measurement reconciliation study with the Department of Energy’s National Renewable Energy Laboratory, and in supporting research currently underway at the University of Texas at Austin Energy Institute and Stanford University as part of its Natural Gas Initiative.